Carbon fibres with ordered graphitic-like aggregate structures from a regenerated cellulose fibre precursor

The production and characterisation of low modulus carbon fibres is reported from a commercially available regenerated cellulose fibre (Cordenka (TM)). The fibres were heat treated before graphitisation at a temperature of 200 degrees C. Fibres were then further heat treated and graphitised at a temperature of 2000 degrees C. Polarised Raman spectra of carbonised/graphitised fibres were recorded. The ratio of two Raman peaks located at similar to 1350 cm(-1) (D-band) and at similar to 1600 cm(-1) (2D band) - the I-D/I-G ratio - was used to follow the onset and development of the carbon/graphitic structure. It is shown, using tensile testing, that single carbon fibres processed at 2000 degrees C have a modulus of similar to 70 GPa and strain at break >2%. A Raman spectroscopic method that follows the shift in the position of the 2D band suggests a modulus of similar to 77 GPa. Transmission Electron Microscope imaging of the fibres reveals a sub-structure containing aggregates of oriented concentric turbostratic carbon domains, some of which are reminiscent of carbon nanotubes. These relatively high strength fibres (1.5 GPa) could be possible alternatives to E-glass fibres in low weight (similar to 30% lighter than E-glass), high volume automotive and marine applications. It is also shown that these fibres can be converted in a woven precursor form to a carbon fibre fabric without the need to weave brittle filaments. (C) 2015 Elsevier Ltd. All rights reserved.